codes for vessels(46-51)

8/3/2019 Codes for Vessels(46-51)

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CODES FOR VESSELS/HEAT

EXCHANGERS

Avinash Nayak. (46)

Shrikantkumar Padhy (47)

Jitendra Patil (48)

Manoj Patil (49)

Ganeshprasad Pavaskar (51)


2/23

History of pressure vessel codes

Boiler explosion on March 20, 1905 in Brockton,

Massachusetts. 58 killed and 117 injured.

Need of legislative rules and regulation for

construction of boilers. The first Boiler and Pressure Vessel Code was

published in 1915.

Necessary changes made and new sections addedas need arose.


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What is a Code?

A code is a standard that has been adopted by

one or more governmental bodies and has the

force of law, or when it has been incorporatedinto a business contract.

Codes specify requirements of design,

fabrication, inspection and testing of pressure

vessels.

Number of national codes have been developedfor pressure vessels by different countries.

In India, the code for pressure vessels is IS-2825


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5/23

WHAT ARE ASME CODES?

It is a standard that provides rules for the

design, fabrication, and inspection of boilersand pressure.

This establishes and maintains design,construction and inspection standards

providing for maximum protection of life and

property.


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ASME Codes - Manufacturer A manufacturer obtains permission to use one of the

stamps through the ASME conformity assessment process.

The manufacturers quality control system is reviewed byan ASME team.

If it meets ASME requirements and the manufacturersuccessfully demonstrates implementation of the program,the manufacturer is accredited by ASME.

The manufacturer then may certify the product as meetingASME standards and apply the stamp to the product.


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Why follow ASME codes?

Excessive elastic deformation including elastic

instability Excessive plastic deformation

Brittle fracture

Stress rupture or creep deformation (inelastic)

Plastic instability and incremental collapse

High strain and low cycle fatigue

Stress corrosion

Corrosion fatigue


8/23

ASME Codes - User

ASME Publications Catalog,

The ANSI Catalog of American National

Standards,

the US governments OSHA General IndustryStandards,

contact a standards organization directly.

http://www.asme.org/catalog


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ASME Codes User

Insurance

Replacement

Proper Compliance

- Size specific

- Jurisdiction

Proper ASME stamps


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The organization of the ASME Boiler and Pressure Vessel Code is

as follows:1. Section I: Power Boilers

2. Section II: Material Specification:

i. Ferrous Material Specifications Part Aii. Non-ferrous Material Specifications Part B

iii. Specifications for Welding Rods, Electrodes, and Filler Metals

Part C

iv. Properties Part D

3. Section III Subsection NCA: General Requirements for Division 1

and Division 2

i. Section III Division 1:

a. Subsection NA: General Requirements

b. Subsection NB: Class 1 Components


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Subsection NC: Class 2 Components

d. Subsection ND: Class 3 Components

e. Subsection NE: Class MC Components

f. Subsection NF: Component Supportsg. Subsection NG: Core Support Structures

h. Appendices: Code Case N-47 Class 1:

Components in Elevated Temperature Service Section III, Division 2: Codes for Concrete Reactor

Vessel and Containment

Section IV: Rules for Construction of Heating Boilers

Section V: Nondestructive Examinations


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Section VI: Recommended Rules for the Care and

Operation of

Heating Boilers

Section VII: Recommended Guidelines for Care of Power

Boilers

Section VIII

i. Division 1: Pressure Vessels Rules for

Construction

ii. Division 2: Pressure Vessels Alternative Rules

Section IX: Welding and Brazing Qualifications

Section X: Fiberglass-Reinforced Plastic Pressure Vessels

Section XI: Rules for In-Service Inspection of Nuclear

Power Plant Components


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Stamps


14/23

Nomenclature


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16/23

Example

A heat exchanger qualifies as a UM stamped

pressure vessel if:

- Design pressure < 15psig

- Internal volume < 1.5 cubic ft. for 150


17/23

Example

A heat exchanger qualifies as a U stamped

pressure vessel if:

- Design pressure > 600 psig

- Internal volume > 1.5 cubic ft. for 150


18/23

Comparison of pressure vessels

Item IS-2825 ASME Code

Section VIII

BS-5500 AD-

Merkblatter

Scope Unfired fusion

welded pressure

vessels

Pressure < 20

N/mm2

Do/Di < 1.5

Di > 150 mm

Water capacity >

50 litres

Welded, riveted,

forged and brazed

vessels

Water capacity>120

gal

Operating pressure >

15 psi

Di>6

Unfired fusion

welded pressure

vessels

Medium and

high pressure

storage vessels

Excludes

transportable

vessels.

Do/Di < 1.7

Vessels and

vessel parts

predominantly

under static

load.

materials Carbon and low

alloy steels, highalloy steel, Cu and

Cu alloys, Al and

alloys, bolting and

casting alloys

Same as IS-2825

Cast iron, linedmaterial cast iron,

ferritic steel

Carbon, ferritic

alloy(low andhigh) and

austenitic steels

All metallic

materials andgraphite, glass.


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Comparison of pressure vesselsItem IS-2825 ASME Code

Section VIII

BS-5500 AD-

Merkblatter

Designpressure

Maximum workingpressure including

static head + 5%

maximum working

pressure.

Maximumpressure at most

severe conditions

Maximumpressure at

most severe

conditions

Based onpermissible

service pressure

Designtempera

-ture

Highest metaltemperature

expected under

operating conditions

Actual metaltemperature

expected under

operating

conditions

Actual metaltemperature

expected

under

operating

conditions +

margin for

uncertainties

Highest walltemperature

expected under

working

conditions


20/23

Comparion of pressure vessels

National code U.T.S Yield strength Sr(rupture

stress)

Creep stress

ASME: VIII

Div: 1

4 1.6 - 1

ASME: VIII

Div-2

3 1.5 - -

BS-1515 4 - - -

BS-1515Part II

2.5 1.5 1.5 1

BS-5500 2.35 1.5 1.3 1

ANCC - 1.5 1.5 -

IS-2825 3 1.5 1.5 1


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Explosions


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In spite of some of the most rigorous, well-

conceived safety rules and procedures ever put

together, boiler and pressure vessel accidents

continue to occur.

In 1980, for example, the National Board of Boiler

and Pressure Vessel Inspectors reported:

- 1972 boiler and pressure vessel accidents, 108injuries and 22 deaths.

The pressure vessel explosions are of course rare

nowadays and are often caused by incorrectoperation or poorly monitored corrosion.


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Safety in boiler and pressure vessels can be

achieved by:

Proper design and construction

Proper maintenance and inspection

Proper operator performance and vessel operation

codes for vessels(46-51)

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